Trailer hitch

ABSTRACT

A trailer hitch comprising a pair of parallel horizontal plates, each having curvilinear projections therefrom and the projections penetrating selected openings provided in an attachment surface, such as a vehicle bumper or extension from the frame, transverse to the horizontal plates. The projections are tilted into the openings to bear on the opposite side of the web of the bumper or frame extension from the plates. Thus the horizontal plates are positioned in relative parallel spaced registry relation. The trailer ball serves as a stud and extends through both registering plates and upon tightening partially closes the space between the plates and secures the hitch in compression relation relative to the attachment surface such as the bumper or frame extension.

United States Patent 1191 Dotterweich 4] TRAILER HITCH [75] Inventor:William E. Dotterweich, East Lansing, Mich.

[73] Assignee: Foote Products, Valley Tow-Rite Division, The Scot andFetzer Company, Lansing, Mich.

{22] Filed: Feb. 14, 1972 21 Appl. No.: 226,122

FOREIGN PATENTS 0R APPLICATIONS France ..L 280/491 E June 26, 1973 [57]ABSTRACT A trailer hitch comprising a pair of parallel horizontalplates, each having curvilinear projections therefrom and theprojections penetrating selected openings provided in an attachmentsurface, such as a vehicle bumper or extension from the frame,transverse to the horizontal plates. The projections are tilted into theopenings to bear on the opposite side of the web of the bumper or frameextension from the plates. Thus the horizontal plates are positioned inrelative parallel spaced registry relation. The trailer ball serves as astud and extends through both registering plates and upon tighteningpartially closes the space between the plates and secures the hitch incompression relation relative to the attachment surface such as thebumper or frame exten sion.

5 Claims, 6 Drawing Figures PAIENTEUJUNZBIQH 3 741 588 I same or 2 FIG.4

welding or by connection to and extension from a vehicle frame. Thepresent hitch utilizes a unique combination of plates and curvilinearprotuberancesto interlock the plates with a vehicle bumper or bumpermounted vertical plate so that the hitch structure is selectivelyremovable, is easy to install and as strongly supportive of a trailer asthe vehicle bumper or frame extension.

The invention looks toward the provision of a trailer hitch useful withnew heavier bumpers as are likely to be required in automotive safetyregulations and which hitch can be removed when not in use by the mereapplication or removal of the ball element.

THE PRIOR ART While hitch devices applied to vehicles for attachment oftrailers are well known, there appear to be no others who have attemptedto provide a hitch supported by curvalinear protuberances from plateswhich protuberances are extended through openings in a bumper or frameextension and where the horizontally referenced plates are in verticalface to face registry and are urged toward each other by the fasteningof the plates as by the ball stud. The closest known suggestion of themounting provisions are found in U.S. letters Pat. No. l,21 1,992 toWinter; U.S. letters Pat. No. 2,595,711 to Schwork', and US. lettersPat. No. 2,3 l2,985 to Bales. These references fail to show adjacentface to face parallel plates in support of a trailer hitch ball andconnected to the vehicle through selected openings in the vehicle bumperor frame extensions.

Accordingly, a principal object of the present invention is to provide anew and useful quickly dismountable trailer hitch which is assembledthrough a bumper or other frame extension.

Another object is to provide a trailer hitch from three parts relatedtogether by a wall such as the hub of a vehicle bumper. These are a pairof horizontal plates each having spaced apart protuberances extendingtherefrom and plates which are assembled in parallel spaced apartjuxtaposed registry. The bumper frame mounting means through which theprotuberance extends and against which the. plates bear on one side andthe protuberances bear on the other, and clamp means urging I the twoplates towards each other and in tight clamping relation against themounting means.

Still another object is to provide a durable bumper mounted trailerhitch which is simple to construct and easy to install.

Other objects, including economy and safety will be increasinglyapparent as the description proceeds.

G ENERAL DESCRIPTION wall substantially transverse to the planes of theplates so that the rear edges of the plates bear upon the wall on oneside and the curvilinear protuberances bear against the wall on theother side. At this point of contact in both plates, the upper and lowerplate are in spaced apart parallel face to face registry. This permitsthe use of a ball hitch stud or other clamping means for urging the 'twoplates toward each other. The more tightly the stud is attached, thetighter the compression between plates and protuberances on the wall.The wall is a web or vertical portion of the bumper of a vehicle and theplates are different in size so that the openings through the wall arenot clustered to overly weaken the wall. The plates are easily detachedby unfastening the hitch ball stud and tilting the protuberances out oftheir openings thereby leaving the bumper wholly uncluttered. Thespacing, as will be seen, may be adjusted for variant wall thicknessesand configurations. While such devices were frowned upon when bumperswere insubstantial, the present safety requirements urging stronger andmore structurally integrated bumpers provide a basis of excellent use ofthe present hitch and when the present hitch is dismounted the bumper isleft uncluttered by any extension therefrom.

IN THE DRAWINGS FIG. 1 is a perspective view of a trailer hitch inaccord with the present invention secured to a vehicle bumper.

FIG. 2 is a composite exploded perspective view of a trailer hitch, thehitch elements of the present invention and indicating the extremesimplicity of the structure.

FIG. 3 is a side elevation view of the trailer hitch of the presentinvention installed through a vertical bumper plate.

FIG. 4 is a top plan view of the structure seen in FIG. 3 and indicatingthe relative disposition of the upper and lower plates in registryrelationship by the hitch ball and stud element.

FIG. 5 is an exploded perspective view of a modified structure in'accordwith the present invention and indicating the variable displacement ofthe plates by adjustment of the protuberances and use of a fillerbuttress.

FIG. 6 is an elevation view as in FIG. 3 but showing the tilt-intechnique in phantom line extending the protuberances into and throughthe vertical plate.

SPECIFIC DESCRIPTION Referring to the drawings and in particular to theFIG. ll thereof, the trailer hitch iii of the present invention is shownsecured to the bumper 12 which is a reinforced extension of a vehicleframe. The trailer hitch Ill includes an upper plate 13 and lower plateM held together with the ball stud 15, the ball portion of which extendsupwardly for engagement with a corresponding connector element on a towbar of a trailer, for example. Openings 16 formed through the upperplate 13 provide safety chain support link connections. The rods 17welded to the upper surface of the upper plate 13 are seen to extendinto and through the web portion 118 of the bumper 12 through theopenings 19. The bumper I2 is considerably stronger than most bumpersnow in common vehicular use and is in accord with safety requirementsseeking added strength and resistance to substantial damage of vehicles.

FIG. 2 shows the interrelationship of the elements shown assembled inthe FIGS. 1 and 3. The ball stud is seen as separable so that the ballis threadably detachable from the stud 21 and it is seen that the stud21 extends upward through the openings 22 in the plate 14 and 23 in theplate 13 for threadable connection to the ball element 20. The lockwasher 24 resists vibrational disconnect as between the stud 21 andplates 14, 13 and ball 20. The registry as between the plates 13 and 14is for parallelity and precise registry of the stud openings 22 and 23.The rods 17 in the plate 13 extend rearwardly therefrom in a risingvertical serpentine or S curve 25 in respect to the horizontal of theplate 13 as shown. The curvature is such as to place the contact surface26 in horizontal displacement from the back edge 27 of the upper plate13, an amount which will be seen to substantially equal the thickness ofthe web 18 of the bumper 12. The lower plate 14 can also be seen toinclude parallel rearwardly extending curvilinear rods 21 which extendrearwardly and curve vertically downwardly in a serpentine or S curveconfiguration. Here, as in the plate 13, the contact surfaces 29 aredisplaced horizontally from the rear edge 30 of the plate 14 by adistance substantially equal to the thickness of the bumper 12.Accordingly, the curvilinear protuberances 2S and 31 in the upper andlower plates 13 and 14, respectively, cooperate with the rear edges 27and 31 of the plates 13 and 14, respectively, to assure substantialspaced apart face to face parallelity as between the two plates 13 and14 when assembled by insertion of the protuberances 25 and 31 throughthe openings 19 and 19a spaced through the bumper 12 to receive theprotuberances 25 and 31 in a tilt-in manner. The vertical spacinginterval as between openings 19 and 19a establish the space intervalbetween the plates 13 and 14. While the plates 13 and 14 may be cast orforged to provide the selected protuberances 25 and 31, respectively,the structure illustrated shows rod stock formed as desired in themating serpentine configurations and then welded, brazed or otherwiseattached to the upper surface of the upper plate 13 and the lowersurface of the lower plate 14, as shown.

In the FIG. 3, the assemblage of FIG. 2 is placed in appropriate tilt-inrelation through the bumper 12 and the plates 13 and 14 are thereuponplaced in parallel opposed face to face relation and in registry forclamping by the stud 21 and internally threaded ball 20. Tightening ofthe stud ball 15 relationship will urge the two plates 13 and 14 closertogether and tightens the grip of surfaces 26 and 29 and edges 27 and 30against the web 18 in a most secure manner.

By reference to FIG. 4, the plate 13 superposed over the plate 14 isbest seen and the spacing of the protuberances 25 and 31 are bestunderstood in spaced relation vertically (FIG. 3) and horizontally toavoid weakening the web 18 at the point of the openings 19 and 190.

In FIG. 6 the tilt-in of the plate 13 is shown to illustrate the simpleassembly and disassembly of the trailer hitch of the present inventionconnected through the opening 19 in the web 18 of bumper 12 and firmlybearing at point 26 and at the edge 27 against the web 18 and securedsolidly and in compression relation on the bumper 12 by the single clampelement of ball stud 6 shown in solid lines bearing on the web 18 onboth sides with the plate 14 finally transverse to the plane of the web18 and with the edge 27 displaced from the contact point 26, thedistance A, substantially equal to the web thickness. The lower plate 14will be understood to be similarly and oppositely tilted into positionas seen in FIG. 3.

The structure seen in FIG. 5 is modified from the previously describedstructure to illustrate an adjustable form of the structure toaccommodate a variety of thicknesses A as from one vehicle to anotherand to conform to curvilinear forms of web in a particular bumper. Whileonly the upper plate 41 is shown, the lower plate can be similarly butoppositely arranged. The rod elements 42 are adjustable by selectingopenings 45 for the fasteners 43 and nuts 44 in the bank of openings 46for selected registry. This adjusts the relative amount of projection ofthe protuberance 47 and in particular, locates the contact surface 48which, upon assembly, engages the web of the bumper on the back side orvehicle side of the bumper. Then by selecting an insert 49, which is aspacer, additional dimensional control may be added to accommodate aselected webbing thickness A (as in FIG. 6) or a displacement equal towebbing thickness plus curvature so that on assembly, the plate 41projects horizontally in spaced face to face parallelity with the lowerplate, similarly provided. Both or either of the adjustments indicatedare useful for modifying the trailer hitches of this invention toparticular bumper or vehicular situations. The stud opening 50 isunderstood as being in register with a corresponding opening in thelower plate to receive the ball stud clamp as in previously describedstructures. The openings 52 indicate the use of rivets or otherfasteners for the spacer element 49 but brazing or welding is alsouseful in some instances and the entire object of the L-shaped spacer isto selectively locate the rear edge 53 for contact against the outboardside of the bumper web.

In operation, the presently described trailer hitches perform well andare easily taken on and off in a matter of minutes. As changes occur inthe strengthening of the bumpers, it is expected that hitches asdisclosed herein will prove most helpful and will be interchangeable asbetween different vehicles.

Having thus described my invention and at least one operative embodimentthereof, others skilled in the art will readily appreciate improvementsand modifications therein and such improvements and modifications areintended to be included herein limited only by the scope of thehereinafter appended claims.

I claim:

1. A trailer hitch comprising:

a pair of horizontal plates and each having a pair of curvilinearprojections of a configuration to pass through registering openings in asubstantially vertical wall of a bumper;

a bumper element having a vertical wall portion and openingstherethrough and through which said projections of said plates may beselectively passed so that said plates are supported by said bumper wallin a parallel relation; and

a hitch stud passing through both of said plates in parallel registereach with the other and compressing said projections and said platesagainst said vertical wall.

2. The trailer hitch of claim 1 wherein the horizontal plates haveserpentine curvilinear projections which extend rearwardly andtransversely of the plane of said plates.

3. The trailer hitch of claim 1 wherein the contact point of saidcurvilinear projection with said wall and said plates at contact withsaid wall is equal to the thickness of said wall whereby said platesproject horizontally from said wall in spaced apart parallel relation.

4. A quickly dismountable trailer hitch of the ball type secured inposition by a single fastener comprismg:

an upper horizontal plate having a projecting portion therefrom and arear edge;

a lower horizontal plate having a projecting portion therefrom and arear edge, said lower plate being positioned in opposed spaced apartregistry with said upper plate and said projections curved transverselyfrom said plates;

a substantial vertical wall having openings therethrough and throughwhich said projections extend and said projections bear. against saidwall when saidplates are in spaced parallel face to face relationengaging the other side of said wall; and

a ball stud element extending upwardly through said plates and securingsaid plates in compression relation to each other and said wall.

5. A ball type trailer hitch comprising:

an upper horizontal support plate and including curvilinear projectionsextending from one side of said upper plate and transversely upwardly ona gentle S curve of serpentine configuration;

a lower horizontal support plate positioned in substantially parallelspaced register with said upper plate and said lower plate including aplurality of curvilinear projections extending from one side of saidlower plate and downwardly in a gentle S curve configuration;

a substantially vertical support wall having openings therethrough inregistry with said projections and against which the said upper andlower plates bear on one side and said curvilinear projections bear onthe other when said plates are in parallel horizontal relation; and

a ball hitch stud element in clamping relation through said upper andlower support plates which upon tightening urges said plates toward eachother and the consequent tilt thereof urging said projections into tightbias relation against said vertical support wall.

1. A trailer hitch comprising: a pair of horizontal plates and eachhaving a pair of curvilinear projections of a configuration to passthrough registering openings in a substantially vertical wall of abumper; a bumper element having a vertical wall portion and openingstherethrough and through which said projections of said plates may beselectively passed so that said plates are supported by said bumper wallin a parallel relation; and a hitch stud passing through both of saidplates in parallel register each with the other and compressing saidprojections and said plates against said vertical wall.
 2. The trailerhitch of claim 1 wherein the horizontal plates have serpentinecurvilinear projections which extend rearwardly and transversely of theplane of said plates.
 3. The trailer hitch of claim 1 wherein thecontact point of said curvilinear projection with said wall and saidplates at contact with said wall is equal to the thickness of said wallwhereby said plates project horizontally from said wall in spaced apartparallel relation.
 4. A quickly dismountable trailer hitch of the balltype secured in position by a single fastener comprising: an upperhorizontal plate having a projecting portion therefrom and a rear edge;a lower horizontal plate having a projecting portion therefrom and arear edge, said lower plate being positioned in opposed spaced apartregistry with said upper plate and said projections curved transverselyfrom said plates; a substantial vertical wall having openingstherethrough and through which said projections extend and saidprojections bear against said wall when said plates are in spacedparallel face to face relation engaging the other side of said wall; anda ball stud element extending upwardly through said plates and securingsaid plates in compression relation to each other and said wall.
 5. ABall type trailer hitch comprising: an upper horizontal support plateand including curvilinear projections extending from one side of saidupper plate and transversely upwardly on a gentle S curve of serpentineconfiguration; a lower horizontal support plate positioned insubstantially parallel spaced register with said upper plate and saidlower plate including a plurality of curvilinear projections extendingfrom one side of said lower plate and downwardly in a gentle S curveconfiguration; a substantially vertical support wall having openingstherethrough in registry with said projections and against which thesaid upper and lower plates bear on one side and said curvilinearprojections bear on the other when said plates are in parallelhorizontal relation; and a ball hitch stud element in clamping relationthrough said upper and lower support plates which upon tightening urgessaid plates toward each other and the consequent tilt thereof urgingsaid projections into tight bias relation against said vertical supportwall.